Components of Variance of Scales With a Bifactor Subscale Structure From Two Calculations of α

Since Cronbach's (1951) elaboration of α from its introduction by Guttman (1945), this coefficient has become ubiquitous in characterizing assessment instruments in education, psychology, and other social sciences. Also ubiquitous are caveats on the calculation and interpretation of this coefficient. This article summarizes a recent contribution (Andrich, 2015) on the use of coefficient α which complements these many caveats. It shows that in the presence of a simple bifactor structure of a scale where unique components of variance are homogeneous in magnitude, three components of variance and the common latent common correlation among the subscales can be calculated from the ratio of two calculations of α, one at the level of the items, the other at the level of the subscales. It was suggested that these two ready calculations and their interpretation, and the reporting of all four indices in the analysis of scales with a subscale structure, would reduce the misinterpretation of this coefficient. An illustrative example of the application of the calculations is also shown.     

Using Consumer Data to Illustrate How the Library Channel Drives Digital Sales

The library channel is often underappreciated as a key part of a publisher’s business strategy. In an age where publishers are constantly seeking new revenue and marketing opportunities, presence in the library—digitally—can yield significant growth. This paper examines the library channel, its business model based on library lending, the performance of eBooks and audiobooks across all subjects, and consumer reading behavior. Digital Book Clubs, a relatively new phenomenon, are also defined and illustrated with examples demonstrating the library’s valuable role in increasing discoverability and ultimately sales.     

Language Acquisition Assisted by the Internet

Abstract

The authors focus on exploiting new methods of language acquisition with the help of the possibilities offered by the Internet. As a new option for computer‐assisted language learning, the Internet is considered to be a source for individual learning and problem oriented teaching in many other areas. Expanding knowledge in parallel in informatics and the English language is an asset. In addition to pointing out starting off sites for ESL teachers and introducing some interesting examples, some criteria of constructing language teaching WWW pages of our own are also listed.     

Differing Roles,Differing Concerns: Using Network Analysis as a Tool to Highlight Diverging Concerns and Priorities Surrounding Teacher Education at Minority-Serving Institutions

Abstract

Minority-serving institutions are important in the production of teachers of color. However, this formative process is not without limitations. This multisite, multistate study relied on network analysis techniques to unveil timely and relevant concerns that students, faculty, and administrators identified as critical toward the strengthening of teacher production.     

The effect of context on students’ reasoning about forces

When attempting to solve closely related problems in science, students will often respond to irrelevant contextual features in the questions rather than generalizing their conceptions over the range of relevant situations. In this study, a group of 40 students (one group of 15‐16‐year‐olds and another of preservice science teachers) was surveyed and interviewed to determine the effect of context on the reasoning which they used to solve problems concerning the forces acting on objects in linear motion. It was found that the younger group of students were influenced by contextual features such as the speed, weight and position of the moving object, the direction of the motion and their own personal experience of the context. There were clearly two types of contextual effects ‐‐ primary and secondary, which are described. The older group of students was generally less affected by context and thus more consistent in their reasoning.